1. Field of the Invention
Embodiments of the present general inventive concept relate to a method of controlling a filter coefficient of a continuous time filter of a data storage device, and more particularly, to a method of controlling a filter coefficient of a continuous time filter of a data storage device, which may draw (and/or calculate) an optimal filter coefficient value considering a flying height change of a magnetic head, and a data storage device to perform the method.
2. Description of the Related Art
Generally, a hard disk drive (HDD), a kind of a data storage device, replays data recorded on a disk by the magnetic head or contributes to a computer system operation by recording user data on the disk.
As the HDD gradually becomes high capacity, high density and miniaturized, Bit per inch (BPI), which is density of a disk turning direction, and Track per inch (TPI), which is density of a radial direction, are on an increasing trend and more delicate mechanisms are required, accordingly. The HDD affects read and write performance of data depending on a flying height of the magnetic head, which is distance between the magnetic head and the disk. The flying height of the magnetic head is changed temporarily or permanently by a use environment of the HDD, e.g., a long time use, changes of a use environment or physical impacts and so on.
The flying height change of the magnetic head affects read or write performance of data. For example, as the flying height of the magnetic head gets lower, the read and write performance is improved but crash-occurring possibility between the magnetic head and a disk is increased by disturbance according to the impacts, and so on. As the flying height of the magnetic head gets higher, the crash occurring possibility may be reduced but the read and write performance is deteriorated.
Conventionally, a target flying height of the magnetic head is determined according to a flying on demand (FOD) value calculated at a beginning of a process, and a test determining filter coefficient of a continuous time filter (CTF) is processed, accordingly. However, an above-mentioned test method may cause an error of a HDD since it doesn't consider a flying height change of the magnetic head according to a use environment of a HDD.